Tweco FP-95 Mini MIG - Manual (Page 35)

SERVICE FIREpOwER Fp-95
Service 5-1 Manual 0-5122
5.01 Cleaning of the Unit
Periodically remove the right side panel (after disconnect-
ing the supply cord from the receptacle) and blow out the
interior with clean, dry, compressed air of not more than
25 PSI air pressure. Do not strike any components with
the air hose nozzle.
5.02 Cleaning of the Feed Rolls
Clean the wire groove on the feed roll at frequent intervals.
This cleaning operation can be done by using a small
wire brush. To clean the wire groove, loosen the pressure
device and lift the feedroll pressure arm. Remove all wire
from the feedhead. Wipe off the bearing roll (the “top” roll
in the feedhead).
5.03 Basic Troubleshooting
The basic level of troubleshooting is that which can be
performed without special equipment or knowledge, and
without removing the covers from the Power Source.
If major components are faulty, then the Power Source
should be returned to an Accredited THERMAL ARC Ser-
vice Agent for repair.
1. Porosity
When there is a gas problem the result is usually porosity
within the weld metal. Porosity always stems from some
contaminant within the molten weld pool which is in the
process of escaping during solidification of the molten
metal.
Contaminants range from no gas around the welding arc
to dirt on the work piece surface. Porosity can be reduced
by checking the following points:
1. Welding dirty, oily, painted, oxidized or greasy
plate.
a. Clean contaminates off the plate.
2. Distance between the MIG torch nozzle and the
work piece.
a. Keep the distance between the MIG torch nozzle
and the work piece to a minimum.
SECTION 5:
SERVICE
2. Inconsistent wire feed
Wire feeding problems can be reduced by checking the
following points:
1. Wire spool brake is too tight.
a. Feed roller driven by motor in the cabinet will
slip.
2. Wire spool brake is too loose.
a. Wire spool can unwind and tangle.
3. Worn or incorrect feed roller size.
a. Use ‘V’ groove drive feed roller matched to the
steel wire size you are welding.
4. Misalignment of inlet/outlet guides.
a. Wire will rub against the misaligned guides and
reduces wire feedability.
5. Liner blocked with slag.
a. Slag is produced by the wire passing through
the feed roller, if excessive pressure is applied
to the pressure roller adjuster. Slag can also
be produced by the wire passing through an
incorrect feed roller groove shape or size. Slag
is fed into the liner where it accumulates, thus
reducing wire feedability.
6. Incorrect or worn contact tip.
a. The contact tip transfers the weld current to
the electrode wire. If the hole in the contact
tip is too large, then arcing may occur inside
the contact tip resulting in the electrode wire
jamming in there. When using soft electrode
wire such as aluminum, the wire may become
jammed in the contact tip due to expansion of
the wire when heated. A contact tip designed
for soft electrode wires should be used.
7. Poor work lead contact to work piece.
a. If the work lead has a poor electrical contact to
the work piece, then the connection point will
heat up and result in a reduction of power at
the arc.
8. Bent liner.
a. This will cause friction between the wire and
the liner thus reducing wire feedability